Such an RFID tag includes an IC chip configured to record information and an antenna connected to the IC chip. In the RFID tag, wireless communication with the reader/writer is performed by the antenna, and thereby information stored in the IC chip is read out, or information is written in the IC chip.
There has been a growing demand for miniaturizing such RFID tags in recent years, and a miniaturized RFID tag disclosed in Patent Literature 1 is already known, for example, as an RFID tag that meets the demand. The antenna of the RFID tag is constituted by a multilayer antenna stacked over the IC chip and integrally joined thereto. The multilayer antenna includes a base material having substantially the same outer dimensions as the IC chip, a first coil formed on the base material, a second coil stacked on the first coil via an insulation film, and a protective film protecting the second coil.
In the RFID tag of Patent Literature 1, the antenna is a multilayer antenna, and therefore has a large number of turns. As a result, the RFID tag is said to be capable of improving antenna efficiency (such as the communication distance). However, no sufficient communication distance has been achieved yet by the RFID tag, and there is room for improvement.